Silica nanoparticle-based hybrid probe for visual fluorometric Fe³⁺ detection in beverage samples

Iron is a vital micronutrient for human physiology, yet its imbalance-whether as a deficiency or in excess-can pose significant health risks. Traditional detection methods for Fe³⁺ ions often face challenges, prompting the development of less toxic and more stable fluorescent probes. In this study, a novel hybrid system was engineered, integrating an organic fluorescent dye (BODIPY) with inorganic silica nanoparticles (SNPs) for the sensitive and selective detection of Fe³⁺ ions. A BODIPY scaffold was selected as a signalling reporter unit and covalently bonded to silica nanoparticles. The resulting probe, BOD-SNP, exhibited a "turn-on" fluorometric response with high sensitivity (LOD = 1.3 μM). Notably, BOD-SNP effectively detected Fe³⁺ ions in complex matrices, including water and beverage samples. It is also an appropriate system for colorimetric detection of Fe³⁺ under a fluorescence lamp using a smartphone based on RGB analysis. This is one of the rare studies exploring the application of silica nanoparticle-based systems for the fluorometric 'turn-on' detection of Fe³⁺ ions, paving the way for advanced analytical applications.